Pivot end contact for electric disconnecting switches



Sept. 9, 1952 c. H. BAYER PIVOT END CONTACT FOR ELECTRIC DISCONNECTING SWITCH Filed Feb. l5, 1951 7 M e e Xg 5 n Paw W O t MH m V btw H m C s b Patented Sept. 9, 1952 iasioms -'VDTEDCONTACTQBLECTRC y l VD ISGONNEC'IING''SWITCHES Charles LfBayr, Wynnewood fPa-.,ras'signor"-to v General-,Electric eCompany, a corporation of switches.

i *Sch 'liifgh' contact pressure 1disconnecti'rrg fswitch'esfvsually'l-involvepivdtallysupportingone 'end1 of''afblade' vtnreilierfo'nz at stationary insulator stackiwithflania-'sso c'ia'tedr operating? `"'riiecli'anisfn -`to swing the free end oi?A blade aboutV the transverse pivot axis into position between the spaced fin'- ge'ifs o'f''a -sihape'd 'stationary 'contact mounted om notlferfinsuflatr aok. The blade .is thenro- @anotnembiectfbf my fmvention fro-fpm.;

*2. Y vide. -a dual zaxis disconnecting. switch ,Blade shaped a't `rits 'pivoted.' end 'to substantially elimi- 'nate'oontat ylou'rning and 'pitting dueto fictra'nei- Youszmatteiz -It is still 'another object of fmy invention-:Lto ffprovide 11a terminalfcontact lfitting fortlre-pivoted end 'of 'a dual 1 axis .disconnecting switch blade '-wliich may be readily replaced, .nithe event that ,pi-vot 'axis 'and 'rotating about its 'longitudinal aids, the terminal ttingfslide's between thenfgersoffa stationary -"contact,ref'er`abl3f of Aal-U- sha'pe'd conguratio'n. The 'terminal fkttin'g -fornisa coaxial extension 'of the'switch-blade and is 'made' essentiallyixshap'ed in 'crossisec- -tion l'coaxial with thelongitudinal `'axis o`f the blade, that'is, 'to haveffour Vor niore-'lri'dges'f'extending axially `thereon. -When -the 'blade is 17a-t one limit of its `vrotational 'trav'el,`-on'e pairofdi'- metrically opposed ridges formin'gon'e ba'r'ftlie X rengages 7theTv iingers 'l''f fthe statiayitact. :As v:the iblade =isf1rotated 1to1 itsfotlie'r rotational '-int, ftii'efengagih'g ridges? oftlie lfttri'g "-wife "Gtlie fingers "liree-foi any "xtraneus Amatter *andiamotli'rgairfof idiametricallyopposed ridges if 612m'- `ingHtheeother'fliarof the .Xfslidesinto olea-n contact'with theffngrs. f

. "The 'ff-novel fifeitu'es land Isc'ope inf my invention are 'pointed 'fot T.wi-'th particolari-ty 'in tli'e ap- Iprender ."'claiins For fa' better understanding-,idf my invention, however, and for furthrobjects and advantages thereof, reference should befiiad toa-the followingfdescription tak'enlinifconrrecton 'withtheiaccornanirfgdrawing. Y 'II-nthedrawing Fig. l-iisa-side "elevatin'ffa "ddal'faxis disconnY-cting"v swtchf'enibody-ing my nfentio'ri; -FigL S112 Jis "an f enlarged sectional *View -offf-afpart" f the switch 'shownr inhFig A11 illustrating more clearly' the'particular features v*of-ni'yin- 'vrti'on Eig. "3 isffafrcutawaylview off-aL artoflthe -sw-ito'h taken alor'ig line @3523 ff in -Fi'g 2; f4 issiin'lar tof-Fig. BfS'eXeLSt lthat'! itf illustrate switch blade and J*contat-t@terniin'al Sttig A.ma different rotational position;Vv and Fig. a 4perspective viewfof a'prferred-eninodinientaiitne contactft'ermin'alr ittirig o jmyl invention.

' haVeTS'h'OW-Ilan'c'- cut connecting and disconnecting switch blade I journaled and supported near its pivoted end within a blade supporting hinge member 2 so as to allow rotation of blade I about its longitudinal axis. Hinge member 2, in turn, is pivo'tally mounted by means of pins 3 on a stationary supporting member such as a cross brace member 4 which is mounted at its left end on a stationary insulator stack 5 (partially shown) and which journals a shaft 6 extending from a rotatably mounted insulator stack 1, partially shown. Stationary cross brace member 4 includes a terminal 8 extending therefrom for connection to an electric circuit, not shown. An operating crank 9 is firmly mounted upon rotatable shaft 6 and universally pivotally connected to a swivel link I9. The swivel link I9 is connected at its other end to a blade rotating mechanism Ilia housed in the upper portion of hinge member 2. When the switch is closed and insulator stack 1 is rotated in the proper direction by a suitable crank means, not shown, so that operating crank 9 is rotated about the axis of shaft 6, the swivel link I9 first actuates blade rotating mechanism Illa to cause blade I to be rotated a limited amount about its longitudinal axis. This causes a fiattened free end II/of blade to be released from high pressure engagement with the ngers of a preferably lUshaped stationary contact I2 which is mounted upon a stationary insulator stack I3 and provided with a terminal I4 for connection to the electric icircuit. Further rotation ofV insulator stack' 1 causes the blade I and hinge member 2 to be swung-upward through approximately 90 degrees, pivoting about the pins 3, to the open vertical position indicated by the dashed lines .in'FigL l. The switch is closed in exactly the reverse process of that just described. The disconnect switch may' alsobe provided with co- .operating arcing horns I5 and I6 mounted respectively on terminal I4 `and free end I I of Yblade I. For 'counterbalancing the blade structure in its swinging movement, an energy-storing means such as a spring-backed piston and cylinder assembly I1 may be linked between cross-brace member 4 and hinge member 2 as shown.

Further detailed description of the salient features and operating characteristics of the disconnecting switch shown in Fig. 1 is not believed to Abe necessary since the specific features of my invention will be described in connection with Figs. 2, 3, 4 and 5. However, for a better understanding of the general type of switch shown in Fig. 1, reference may be had to U. S. Patent 2,531,165, issued November 21, 1950, to E. Scheuermeyer and assigned to the same assignee as that of the pres- ;.ent invention.

Referringnow to Figs. 2, 3 and e in which the .pivoted end of blade I is shown in more detail, a terminal contact tting I8, illustrated more clearly in Fig. 5, is shown fastened by suitable Ameans such as bolts I9 and 20 to extend coaxially from blade I and form the pivoted end-thereof; A rib 2 I lmay be provided on tting I8 to engage the surfacesof a diametral slot 22 provided in blade I to reduce any shear stress which might be transmitted to bolts I9 and 20 as blade I is rotated. -The tting I8 includes a base portion 23, ,suitably shaped' to be fastened to blade I, and ouraxially extending ridges 24. 25, 26. and 21 forming a body essentially X-shaped in cross section. Ridges 24 and 26 are diametrically opposed; as are ridges '25 and 21, and the outer surfacesof the-ridges are radiused to form surface elements of a cylinder from which the tting I8 might be made. Ridges 24 and 25 lie at an angle with each other which is the angle through which blade I is rotated about its longitudinal axis during opening or closing of the switch.

To make electrical contact with the terminal tting I8, one or more stationary contacts, preferably U-shaped in configuration, such as contacts 28 and 29, are mounted in aligned relationship, by suitable fasteners such as bolts 30 and 3I, within the left end of cross-brace member 4 adjacent the pins 3. Each stationary contact includes a pair of flexible fingers, that is, contact 28 includes linger 32 and a finger not visible in the drawing, and contact 29 includes fingers 33 and 34, which are in high pressure contact with a pair of diametrically opposed ridges on tting I8. To bias the two fingers of each contact toward one another and insure adjustable high pressure contact thereof with the ridges of fitting I8, fastener means such as shafts 35 and 36 are extended through the fingers, and spring biasing means, such as springs 31 and 38, are secured in compression on the extremities of the shafts. The use of nuts, such as nuts 39 and 40, on threaded shafts 35 and 36 permits the biasing force exerted by springs 31 and 38 to be readily adjustable. To permit the ridges of fitting I8 to be easily rotated into high pressure engagement with the ngers andto provide continuous contact with fitting I8, rounded, smooth, inwardly extending projections 4I and l2 are provided on the fingers.

When the blade I is fully closed, as indicated in Figs. l, 2, and 3, a path of electrical conduction is provided through the switch from terminal 8 through cross-brace member 4, U-shaped contacts 28 and 29, terminal fitting I8, blade I, and contact I2 to terminal I4.

Assuming for purposes of illustration that the blade I and fitting I8 are rotated clockwise about their longitudinal axis, as viewed Vin Fig. 3, through the angle subtended between ridges 25 and 21 to release the flat end I I from high pressure engagement with contact I2, the projections 4I and 42 are long enough so that ridges 26 and 24 engage the fingers of contactsY 28 and 29 before ridges 21 and 25 break engagement with the ngers. When the blade Ihas been fully rotated through the angles subtended by ridges 26 and 21, fitting I8 is then disposed with ridges 24 and 26 in engagement with the fingers of contacts 28 and 29 as shown by Fig. 4. The blade I and hinge member 2 may then be swung upward about pins 3 to open the switch whereupon the axis of blade I and iitting I8 is swung approximately to a vertical position. The ridges 24 and 25, nevertheless, remain at all times during the swinging action in high pressure engagement with the ngers of contacts 28 and 29. Thus, direct electrical connection between blade I and cross-brace member 4 is never broken and the disconnecting action of the switch takes place entirely at end VII ofblade I. This is particularly desirable because if such pivot end connection is made after or broken before the respective connection or disconnection' at the free end of the blade, arcing,r might occur at contacts 28 and 29 instead of at -arcing horns I5 and I6, and damaging current might iiow through link I6 and assembly Il which, as a rule, are not designed to carry heavy current.

In Fig. 4 the fitting I8 is shown in a position, assumed for purposes of illustration corresponding to a position of free end I I resting loosely in stationary contact I2, with ridges 24 and 126 engaging the ngers of the contacts 28 and 29.V As blade I and tting I8 are rotated counterclockwise about their longitudinal axis to cause high pressure contact between free end II and stationary contact I2, the ridges 24 and 2B wipe the inner surfaces of the finger depressions clean of any extraneous matter which might have been deposited thereon. Thus, positive, clean contact with no burning or pitting is assured between ridges 25 and 21 and the fingers when the blade I is fully closed as shown in Fig. 3. Moreover, during the rotation ofblade I on the transverse axis, the ridges 24 and 26 are maintained in rotational wiping engagement with the inwardly extending projections 4I and 42 so as to scrape any dirt, ice or other extraneous matter therefrom. Such extraneous matter can fall freely from all contact surfaces during the rotation of blade I on its. transverse axis. Likewise, when the ridges 25 and 21 additionally wipe the inwardly extending contact surface projections 4I and 42, any addi- 6 true spirit and scope of the foregoing disclosure. What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a switch blade having dual axis pivotal mounting means at one end for rotation of the blade on both a transverse axis and the horizontal axis of the blade, a current cone ducting terminal mounted on the one end of the tional extraneous matter removed therefrom can freely fall way particularly during any subsequent rotation of the switch blade I on its transverse axis. As a result, such extraneous matter is effectively disposed and prevented from accumulating on any contact surfaces.

It will be apparent that my invention includes the use of a single blade provided at its pivoted end with ridges shown and describedY hereinbefore for a separate terminal tting. However, by making the terminal fitting I8 separately and attaching it to the end of the blade, the terminal fitting I8 may be easily replaced without replacing the entire blade should any excessive wear or damage occur to the rubbing surfaces which en-g Y gage the stationary contacts.

While the present invention has by reference to a particular embodiment thereof, it will rbe understood that numerous modifications may be made by those skilled in the art without actually departing from the invention. I, therefore, aim in the appended claims to cover all such equivalent variations as come within the been describedposed ridges extending parallel with the longitudinal axis of the blade, and stationary contacts mounted on opposite sides of the terminal for engaging one set of diametrically opposite ridges therebetween during the rotation of the blade on the transverse axis and the other set of ridges therebetween upon rotation of the blade on the longitudinal axis.

2. In combination, a switch blade having dual axis pivotal mounting means at one end for rotation of the blade on a transverse axis and on the longitudinal axis of the blade, a current conducting terminal mounted on the one end of the blade and having an X-shaped cross section coaxial with the longitudinal axis of the blade, and a U-shaped stationary contact mounted to straddle the terminal for engaging the ends of one bar of the X therebetween during rotation of the blade on the transverse axis and the ends of the other bar of the X therebetween upon rotation of the blade on the longitudinal axis.

' CHARLES H. BAYER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

